kc3-lang/angle/src/compiler/preprocessor/Input.h

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• Hash : 26e355b8
  Author :
  Date : 2015-08-14T14:16:19
  

  Add full support for line continuation in the preprocessor
  
  Re-landing earlier change with constant signedness fixed (was causing
  build issues on Linux).
  
  Line continuation in ESSL 3.00 needs to be processed before tokenization,
  since tokens can span the line continuation. On the other hand, ANGLE's
  tokenizer keeps track of line numbers, and whenever a line continuation
  appears the line number still needs to be incremented by one, just like
  on a regular newline.
  
  That's why line continuation is now implemented as follows: when the
  shader strings are concatenated in Input, they are also checked for line
  continuation. Whenever line continuation is encountered, the string
  is cut before that point. When the tokenizer asks for more input, the
  string starting from the character after line continuation is passed
  to it, and the line number is incremented from Input. This way the
  tokenizer can parse tokens that span multiple lines - it never sees the
  line continuation - but still keeps track of the line number correctly.
  
  Relevant spec is in ESSL 3.00 section 3.2 "Source strings".
  
  Support for line continuation also applies to ESSL 1.00. ESSL 3.00
  spec section 1.5 says that line continuation support is mandated when
  an ESSL 1.00 shader is used with the OpenGL ES 3.0 API, and is optional
  when ESSL 1.00 is used with the OpenGL ES 2.0 API.
  
  TEST=dEQP-GLES3.functional.shaders.preprocessor.line_continuation.*
       (all pass),
       angle_unittests
  BUG=angleproject:1125
  
  Change-Id: Ic086aacac53cd75bf93c0fda782416501d2f842b
  Reviewed-on: https://chromium-review.googlesource.com/294200
  Reviewed-by: Jamie Madill <jmadill@chromium.org>
  Tested-by: Olli Etuaho <oetuaho@nvidia.com>
  

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• src/compiler/preprocessor/Input.h

• //
  // Copyright (c) 2011 The ANGLE Project Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  //
  
  #ifndef COMPILER_PREPROCESSOR_INPUT_H_
  #define COMPILER_PREPROCESSOR_INPUT_H_
  
  #include <stddef.h>
  #include <vector>
  
  namespace pp
  {
  
  // Holds and reads input for Lexer.
  class Input
  {
    public:
      Input();
      Input(size_t count, const char *const string[], const int length[]);
  
      size_t count() const
      {
          return mCount;
      }
      const char *string(size_t index) const
      {
          return mString[index];
      }
      size_t length(size_t index) const
      {
          return mLength[index];
      }
  
      size_t read(char *buf, size_t maxSize, int *lineNo);
  
      struct Location
      {
          size_t sIndex;  // String index;
          size_t cIndex;  // Char index.
  
          Location()
              : sIndex(0),
                cIndex(0)
          {
          }
      };
      const Location &readLoc() const { return mReadLoc; }
  
    private:
      // Skip a character and return the next character after the one that was skipped.
      // Return nullptr if data runs out.
      const char *skipChar();
  
      // Input.
      size_t mCount;
      const char * const *mString;
      std::vector<size_t> mLength;
  
      Location mReadLoc;
  };
  
  }  // namespace pp
  
  #endif  // COMPILER_PREPROCESSOR_INPUT_H_
  

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